Abstract

Objective: This study aims to investigate the clinical results of applying laser iridotomy to early primary angle-closure glaucoma.

Method: One hundred forty-eight patients with early primary angle-closure glaucoma were selected as research subjects. They were divided into observation and control groups. Each group included 74 patients. The observation group underwent laser iridotomy treatment with mannitol and pilocarpine. The control group merely received mannitol therapy along with pilocarpine. Results were analyzed retrospectively. The effective rate of treatment and the levels of intraocular pressure and visual acuity after treatment in the two groups were compared.

Results: The effective rate of treatment of the observation group (83.8%) was significantly higher than that of the control group (68.9%), and the intraocular pressure and visual acuity of the observation group (19.67 ± 2.37 and 0.7 ± 0.2, respectively) were much better than those of the control group (25.06 ± 1.67 and 0.4 ± 0.1, respectively). The difference was statistically significant (P<0.05). The gap in the anterior chamber angle of the treated patients significantly increased compared with that before treatment.

Conclusion: Laser iridotomy for the clinical treatment of early primary angle-closure glaucoma effectively reduces the intraocular pressure and improves the acuity level of patients; it also increases the gap in the anterior chamber angle. The effective rate of treatment is high, so the treatment improves the quality of life of patients. Therefore, this treatment can be popularized in clinical applications.

Keywords

Laser iridotomy, Early primary, Angle-closure glaucoma.

Introduction

Primary angle-closure glaucoma is an ophthalmic disease
caused by the angle closure of the anterior chamber and water
discharge, which is common in old people aged between 50
and 70. Mild cases show decreased visual acuity and
intraocular pressure. For serious illness, the blindness rate is
high. Thus, much inconvenience is caused. Currently, the
common clinical treatments are drug therapy (mannitol with
pilocarpine [1], nimodipine) and surgical treatment (laser
iridectomy [2], ultrasonic phacoemulsification). To investigate
the clinical results of applying laser iridotomy to early primary
angle-closure glaucoma, we selected 148 patients with early
primary angle-closure glaucoma as research subjects from
March 2012 to December 2015. The results were analyzed
retrospectively. The specific circumstances are shown below.

Materials and Methods

Patients

We received 359 patients with early primary angle-closure
glaucoma for treatment in our hospital’s Department of
Ophthalmology from March 2012 to December 2015. We randomly selected 148 patients as the research objects. The
diagnostic codes [3] were as follows: impaired vision, eye
pain, increasing intraocular tension (more than 40 mmHg),
corneal bedewing, corectasis, scleral atrophy, aqueous flare,
scleral adhesion, and translucent white or milky white opaque
spot in the anterior capsule of lens. For the inclusion criteria,
the 148 patients in this study were all diagnosed with early
primary angle-closure glaucoma; patients in other departments
of ophthalmology disease or special disease interference were
excluded after a comprehensive examination. All patients had
no history of primary angle-closure glaucoma. For the
exclusion criteria, patients with high blood pressure, high
cholesterol level, heart disease, diabetes, and other diseases or
have a low operative tolerance for mannitol and pilocarpine as
well as laser iridotomy were not included. All patients were
randomly divided into observation and control groups after
obtaining the consent of the patients and their families. The
observation group comprised 74 patients aged between 53 and
68 years. The control group also included 74 patients aged
between 49 and 64 years. The patients in the two groups have
the same course of disease (within 1 month), appropriate
admission time, physical characteristic (eucrasia), education
(junior high school degree or above), and home situation (wellto-
do family). Therefore, they were comparable (P>0.05).

Clinical treatment

Control group: We used pilocarpine eye drops (Wuhan Five
King Pharmaceutical Co., Ltd.) and intravenous mannitol
(Jiangsu Hengrui Pharmaceutical Limited by Share Ltd.) for
patients. Two to three drops of pilocarpine eye drops were
applied at an interval of 2-4 h. Mannitol (250 mL) was injected
once daily at a controlled injection rate of 4-5 mL/min.

Observation group: We adopted laser iridotomy [4] on the
basis of the drug treatment in the control group. Preoperative
patients were asked to follow the principle of water for a few
times and avoid being in a dark environment for a long time.
Nine points in the affected eye were reduced to three points
near the periphery of the iris laser blasting pore (German Zeiss
YAG laser burning consisted of three pulses, with an average
energy of 15.2 mJ and an iris incision diameter of 1-2 mm.

Observed indicator

Through clinical observation, the treatment [5] of patients was
divided into obviously effective, effective, and ineffective
(obviously effective: eye discomfort was eliminated, and
intraocular pressure and strength levels returned to normal;
effective: intraocular pressure decreased and visual acuity
improved, but a sense of discomfort remained; ineffective:
after the treatment, the condition changed, but intraocular
pressure and visual acuity were unchanged). The patients were
told to measure intraocular pressure and visual acuity before
and after the treatment.

Statistical analysis

SPSS13.0 was utilized for the statistical analysis of data.
Measurement data were expressed as mean ± standard
deviation (͞x ± s). T test, counting the data by (n, %), and chi
square test were utilized. P<0.05 meant that the difference was
statistically significant.

Results

By comparing the effective treatment rates of the two groups of
primary angle-closure glaucoma patients, we determined that
the effective rate of treatment of the observation group was
significantly higher than that of the control group. The
difference was statistically significant (P<0.05), as shown in Table 1.

Table 1. Comparison of the effective treatment rates of the two groups.

The intraocular pressure and visual acuity of the patients were
recorded before and after the treatment. The intraocular pressure and visual acuity of the observation group were much
better than those of the control group. The difference was
statistically significant (P<0.05), as shown in Table 2.

Groupa

Intraocular pressure (mmHg)

Visual acuity

Before treatment

After treatment

Before treatment

After treatment

OG (n=74)

42.39 ± 3.15

19.67 ± 2.37

0.3 ± 0.1

0.7± 0.2

CG (n=74)

41.23 ± 3.26

25.06 ± 1.67

0.2 ± 0.1

0.4 ± 0.1

t

3.362

12.431

6.735

12.274

P

P>0.05

P<0.05

P>0.05

P<0.05

aOG: Observation Group; CG: Control Group

Table 2. Comparison of the intraocular pressure and visual acuity of
the two groups.

The gap in the anterior chamber angles of the primary angleclosure
glaucoma patients was compared before and after the
treatment, as shown in Figures 1-4. The comparison showed
that the anterior chamber angle space significantly increased,
which is conducive to the exclusion of room water and the
remission of the disease.

Figure 1. Nine points before laser iris resection.

Figure 2. Nine points after laser iris resection.

Figure 3. Three points before laser iris resection.

Figure 4. Three points after laser iris resection.

Discussion

Laser iridotomy involves the use of a laser instrument with
nine ocular points reduced to three near the periphery of the
iris at the blasting pore, thus directly opening the anterior
chamber angle, solving the problem of aqueous barrier
discharges, and balancing the real pressure to restore the
physiological aqueous humor drainage pathway. This method
[6] is an effective means to cure primary angle-closure
glaucoma and protect the visual function of patients. With the
rapid development of medical technology, conventional drug
treatment can no longer meet the needs and requirements of
patients. Patients with diseases want rapid cure and require that the prognosis is good. Therefore, a scientific and effective
treatment method is particularly important. Scientists have
stated that [7] the operations of all patients are successful for
one time, with no iris hole closure.

The postoperative corneal endothelial cell count (2288.14 ±
394.01) and the preoperative one (2338.19 ± 362.54) have no
statistically significant differences (P>0.05). However, the
postoperative peripheral anterior chamber depth has
significantly deepened (a total of 46 cases) compared with the
preoperative one (P<0.05). Thus, the clinical results of
applying laser iridotomy to early primary angle-closure
glaucoma are obvious. The symptoms of patients are
controlled, and the feasibility [8] of laser iridotomy, which can
effectively improve the condition of patients, is accepted by
patients and the society. In this study, the effective treatment
rate of the observation group (83.8%) was significantly higher
than that of the control group (68.9%). The intraocular pressure
and visual acuity (19.67 ± 2.37 and 0.7 ± 0.2, respectively) of
the former were significantly better than those of the latter
(25.06 ± 1.67 and 0.4 ± 0.1, respectively). The difference was
statistically significant (P<0.05).

Conclusion

Laser iridotomy for the clinical treatment of early primary
angle-closure glaucoma effectively reduces the intraocular
pressure of patients, improves their acuity level, and increases
the gap in the anterior chamber angle. The effective rate of the
treatment is high, so the treatment improves the quality of life
of patients. Therefore, this treatment can be popularized in
clinical applications.